If two people have the same grandfather, they are siblings or first cousins. If two people have the same great grandfather, they are siblings, first cousins, or second cousins to each other. If two people have the same great great grandfather, they are siblings, first cousins, second cousins, or third cousins.
Two people who have the same great great grandfather are third cousins, second cousins, or first cousins, depending on how their descent runs for the great great grandfather. Since the two people have different surnames one or both of them are descended from a daughter, granddaughter or great granddaughter of the great great grandfather, and one or both of those women followed the custom of giving her children her husband's surname.
There would be no legal impediment provided that was the only common ancestor. I presume as they do not also share the same great grandmother that the great grandfather had children by two women.
Your great grandfather's half-sister is your great great aunt, the same as his full-sister is.
Your great uncle is the brother of one of your grandparents, so his grandfather is also the grandfather of one of your grandparents. The grandfather of your grandparent is your great great great grandfather.
Your grandma's brother is your parents' uncle, so he is your great uncle. if he got married and had a son, then your parents now have a cousin. People with the same grandparents are first cousins. People with the same great grandparents are second cousins. This man is one generation away from you, so he is your second cousin, once removed.
No, cousin and great aunt are very different relationships. Your great aunt is the sister of your grandfather or grandmother. Your first cousin is the child of your aunt or uncle. (Your aunt and uncle are sister and brother of one of your parents.)
You would be 2nd cousins....or your great uncle. you would be a great niece or nephew. Now if you didn't know the answer to your own question, you wouldn't be a very great niece or nephew ! :/
Yes.
This is a nonsense question - because your great grandfather and his sister share the same grandmother, so there is no need to introduce the sister into the question You------------great great great grandchild father--------------- great great grandchild grandfather ---------------great grandchild great grandfather ----------------grandchild great grandfather's mother ----- daughter great grandfather's grandmother
The basic rule is: two people the same number of generations away from a common ancestor are Nth cousins, where N is the number of generations; for people who are not the same number of generations from a common ancestor, they're Nth cousins M times removed where N is the number of generations away from the common ancestor for the one most closely related to that ancestor, and M is the difference in the number of generations removed from the ancestor.This should go without saying, but you always take the shortest possible chain. Two people who have the same grandfather will also of necessity have the same great-grandfather, but you trace it back to the closest possible ancestor. Also, people with the same parents are siblings, not "zeroth cousins".A couple of examples:Two people have the same grandfather. There's one generation between them and their grandfather, so they're first cousins.Person X is the grandfather of person A and the great-grandfather of person B. Persons A and B are first cousins (one generation between X and A) once removed (1 generation difference in the two chains).Person Y is the great-great-grandfather of person C and the great-great-great-great-grandfather of person D. Persons C and D are third cousins (three generations between Y and C) twice removed (two generations difference in the chains).
Your great grandfather's half-sister is your great great aunt, the same as his full-sister is.